Near-daily monitoring of surface temperature and channel width of the six largest Arctic rivers from space using GCOM-C/SGLI

Spatio-temporal changes in water temperature and discharge of the Arctic rivers are important variables to be observed not only for estimating runoff contributions from snow melt, rainfall, thawing permafrost over continents but also assessing their impacts on sea-ice marine ecosystem. Nevertheless, number ground gauging stations frequency in-situ measurements has been decreasing since 20 Century due shrinkage budgets maintaining stations. In this study, we explored possibility perform near-daily monitoring river surface (RST) channel width (RCW) space using a Japanese satellite-borne optical sensor named SGLI which can observe radiances at spectral bands near-ultraviolet thermal infrared regions same spatial resolution 250-m global scale. River brightness (RSBT) measured with TIR band was used as RST without atmospheric correction. RCW derived widths pixels identified along channels reflectances visible shortwave bands. Analysis results two-year data acquired 2018 2019 show that RSBT retrieved successfully observations daily basis after applying spatio-temporal interpolation. The accuracies evaluated temperatures about 2.57 K interpolation (and 1.84 lower observation frequencies). Retrieved RCWs correlated well discharges indicating potentials assess variations melt precipitation within basin. Thus, reconstruct continental heat flux flowing into Ocean.